In recent years, a technique of attaching an input device referred to as a touch panel or a touch sensor to a display surface of a display apparatus and sensing and outputting an input position when input operations are performed by contacting the touch panel with a finger or an input tool such as a touch pen has been known. Such display apparatuses having a touch panel do not need an input device such as keyboard, mouse or keypad, and are thus widely used in portable information terminals such as mobile phones in addition to computers.
One sensing method for sensing contact positions which a finger or the like is in contact with the touch panel is the electrostatic capacitance method. In an electrostatic capacitive touch panel, a plurality of capacitive elements each made up of a pair of electrodes disposed to be opposed to each other with a dielectric layer interposed therebetween, that is, a driving electrode and a sensing electrode are provided in a plane of the touch panel. Then, the input positions are sensed by utilizing the characteristics that the electrostatic capacitance of capacitive elements varies when performing input operations by contacting the capacitive elements with a finger or an input tool such as a touch pen.
Such a display apparatus includes a display region and a peripheral region positioned around the display region, and driving electrodes and sensing electrodes for sensing an input position are arranged in the display region. For example, Japanese Patent Application Laid-Open Publication No. 2013-16141 (Patent Document 1) describes a touch screen panel including a thin film substrate which is divided into an active region and an inactive region positioned around the active region and a sensing pattern formed in the active region of the thin film substrate.